Key parameters at a glance

A radius of 1.88 Earth radii
A mass of 4.19 Earth masses
Surface gravity around 1.19 g
An orbital period of 21.091 days
Semi-major axis 0.1420 AU
Equilibrium temperature 606 K (333 °C)
Distance from Earth 2,052.40 light-years
Earth Similarity Index 0.462
Travel time at Voyager 1 speed 36,194,105 years

Kepler-1644 b Planet Profile

Physical Specs

Radius

1.88 R⊕

Radius (Jupiter)

0.168 R♃

Mass

4.19 M⊕

Mass (Jupiter)

0.013 M♃

Density

3.47 g/cm³

Surface Gravity

1.19 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.462

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#153of 1176

top 12.9%

This planet

1.88R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-137 c 1.88 R⊕ Kepler-291 c 1.88 R⊕ TOI-286 c 1.88 R⊕

Metric	Earth	Kepler-1644 b	Jupiter
Radius (R⊕)	1.00	1.88	11.21
Mass (M⊕)	1.00	4.19	317.83
Density (g/cm³)	5.51	3.47	1.33
Surface Gravity (g)	1.00	1.19	2.53
Insolation (S⊕)	1.00	31.86	0.037

Star Catalogue Identifiers

TIC

TIC 279917005

Gaia DR2

Gaia DR2 2131523450748131456

Gaia DR3

Gaia DR3 2131523450748131456

System

Kepler-1644

Percentile among Super-Earth cohort

Radius 1.880 R⊕ · percentile 86 / cohort 1176

Mass 4.190 M⊕ · percentile 79 / cohort 1176

Orbital period 21.09 d · percentile 86 / cohort 1164

Distance 629.27 pc · percentile 57 / cohort 1171

ESI 0.462 · percentile 69 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

21.091 days

Semi-major axis

0.1420 AU

Eccentricity

0.000

Inclination

87.63 °

Year Length

A year here lasts approximately 21.09 Earth days (5.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1420 AU.

Transit Fingerprint

Depth

0.045 %

Duration

4.629 h

Impact parameter b

0.600

Rp / R★

0.020127

Transit midpoint (BJD)

2,454,966.9620

Photometric dip

Transit produces a flux drop of 446 ppm lasting ≈ 4.63 h.

Extended Orbital Architecture

Planet / star radius ratio

0.020127

Semi-major axis / stellar radius

20.080

Impact parameter (b)

0.600

Transit mid-time (BJD)

2,454,966.9620

Angular separation (arcsec)

0.22600

Eq. Temperature

606K

(333 °C)

Insolation (S⊕)

31.86

Earth = 1.00

Earth Similarity (ESI)

0.462

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Morton et al. 2016

Instrument

Kepler CCD Array

Publication

2016-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at Kepler (12 shown).

Kepler-1512 b · Rocky Terrestrial Kepler-1410 b · Super-Earth Kepler-560 b · Super-Earth Kepler-1389 b · Super-Earth Kepler-1450 b · Super-Earth Kepler-1544 b · Super-Earth Kepler-1459 b · Super-Earth Kepler-1638 b · Super-Earth Kepler-737 b · Super-Earth Kepler-1185 b · Super-Earth Kepler-1178 b · Rocky Terrestrial Kepler-1040 b · Sub-Neptune

Host System: Kepler-1644

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,499 K — cooler than the Sun (5,778 K)

Estimated Age

4.27 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.860 R☉

Stellar Mass

0.890 M☉

Metallicity [Fe/H]

-0.10

Extended Stellar Properties

Surface gravity (log g)

4.530 dex

Stellar density

1.009 g/cm³

Metallicity ratio

[Fe/H]

Distance

629.27 parsec

Light-years 2,052.40 ly

V-band magnitude

14.40 mag

Voyager-speed travel 36,194,105 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.788 mas

Total Proper Motion

17.794 mas/yr

PM Right Ascension

-2.44 mas/yr

PM Declination

-17.63 mas/yr

Galactic Cartesian (pc)

x = 0.178 · y = -0.644 · z = 0.744

Equatorial (J2000)

RA 285.47505° · Dec 48.03484°

Galactic ℓ, b

78.260° · 18.173°

Ecliptic λ, β

301.119° · 69.807°

HTM-20 index

-62232966